參數(shù)資料
型號(hào): HD404668
廠商: Hitachi,Ltd.
英文描述: Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
中文描述: 低電壓如同在微機(jī)芯片的DTMF產(chǎn)生電路(帶雙音多頻電路的低電壓微計(jì)算機(jī))
文件頁數(shù): 91/142頁
文件大?。?/td> 894K
代理商: HD404668
HD404669 Series
91
DTMF Generation Circuit
The MCU provides a dual-tone multifrequency (DTMF) generation circuit. Figure 69 shows a block
diagram of the DTMF circuit. A DTMF signal consists of two sine waves corresponding to the numbers
and symbols on a telephone keypad. DTMF signals are used to access telephone switching equipment.
Figure 70 shows the DTMF frequency matrix.
The OSC clock (400 kHz, 800 kHz, 2 MHz, 3.58 MHz, 4 MHz, 7.16 MHz, or 8 MHz) is changed into
seven clock signals through the division circuit (1/2, 1/5, 1/9*, 1/10, 1/18*, and 1/20). The DTMF circuit
uses one of the seven clock signals, which is selected by the system clock select register 1, 2 (SSR1: $029,
SSR2: $02A) depending on the OSC clock frequency. The DTMF circuit has transformed programmable
dividers, sine wave counters, and control registers.
The DTMF generation circuit is controlled by the following three registers.
相關(guān)PDF資料
PDF描述
HD404669 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
HD407A4669 Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit(帶雙音多頻電路的低電壓微計(jì)算機(jī))
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HD404668H 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD404669 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD404669H 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit
HD404669SERIES 制造商:未知廠家 制造商全稱:未知廠家 功能描述:
HD404676H 制造商:未知廠家 制造商全稱:未知廠家 功能描述:4-Bit Microcontroller